The present invention relates to an apparatus for cleaning a teat of an animal, comprising a substantially cylindrical teat cleaning cup intended to be attached to a teat to be cleaned, wherein the teat cleaning cup comprises nozzle means for injecting a cleaning liquid into the teat cleaning cup and drainage means for draining used cleaning liquid from the teat cleaning cup.
The invention also relates to a method for cleaning an animal teat, comprising the step of attaching a substantially cylindrical teat cleaning cup onto a teat to be cleaned during a cleaning session.
Finally, the invention relates to the use of the above mentioned method and apparatus for cleaning a teat in an automatic robot milking system.
A problem when milking dairy animals, such as cows, is how to ensure that the teats of the animal are clean before milking commences. For this reason various machines have been proposed for cleaning the teats.
It is for instance known from EP 0 801 893 to use a device intended for cleaning and pre-milking teats, having teat cups comprising a plurality of nozzle holes for spraying a cleaning liquid onto teats inserted into said teat cups. When the teat cleaning is accomplished the teat can be pre-milked by means of a particular pre-milking cup portion which is moveable inside the teat cup. However, this device suffers from several disadvantages:
Firstly, it is not possible to increase the cleaning liquid flow through the nozzle holes without increasing the total fluid flow consumption through the cleaning device.
Secondly, the nozzle holes are arranged so as to spray the cleaning liquid almost directly against the teat. The animal may experience discomfort when they are exposed to a direct impact of the cleaning liquid.
Thirdly, spraying a cleaning liquid onto the teat in this way do not adequately clean the tip of the teat. This is very important since dirt and germs present in the opening of the milk canal may contaminate the collected milk.
Fourthly, while the skin of a teat usually is wrinkled dirt is easily stuck in the wrinkles. The dirt is difficult to remove even though spraying or flushing is performed through nozzle holes generously and uniformly distributed along the whole inside of the teat cup.
Fifthly, the teat cup includes moveable parts which involves an unnecessarily complicated design.
The object of the invention is to eliminate the above mentioned drawbacks so as to prepare an animal to a milking session that subsequent extraction of milk do not contain any contaminants.
An other object is to accomplish the above mentioned preparation in an animal friendly manner without causing any harm to the animal.
These objects are obtained by an apparatus as initially defined which is characterised in that:
said nozzle means comprises at least a first and a second group of nozzle members separated circumferentially in the teat cleaning cup;
a cleaning liquid supplying means is connected to each group of nozzle members; and
means for alternating the supply of cleaning liquid to the groups of nozzle members through said liquid supplying means are provided so as to generate by said groups of nozzle members pulsating jets of cleaning liquid acting on the teat to be cleaned.
The object is also obtained by a method as initially defined which is characterised by:
alternating a step of injecting, into an inner space of the teat cleaning cup, a cleaning liquid through a first group of nozzle members with at least one other step of injecting, into said inner space of the teat cleaning cup, a cleaning liquid through at least a second group of nozzle members separated circumferentially from the first group of nozzle members so as to generate pulsating jets of cleaning liquid acting on the teat; and
draining used cleaning liquid from said teat-cleaning cup.
By said apparatus and said method, respectively, is achieved a satisfactory cleaning result of the teat without subjecting the animal to discomfort. Consequently, less milk will be discarded due to presence of contaminants in the extracted milk.
According to a preferred embodiment of the invention vacuum supplying means is provided for applying an under-pressure within said teat cleaning cup. Hereby is achieved that the drainage of the cleaning liquid as well as the injection of the cleaning liquid through said groups of nozzle members is improved.
Preferably, said cleaning liquid supplying means is comprised from cleaning liquid conduits, each connected to one of said groups of nozzle members, in fluid communication, via respective cleaning liquid valves, with a cleaning liquid supply and in fluid communication, via respective compressed-air valves, with a compressed-air supply. Hereby is achieved that the cleaning liquid may be injected into the teat cleaning cup in a controlled way.
Advantageously, said apparatus comprises a detergent agent supply connected to at least one of said cleaning liquid conduits downstream of said cleaning liquid valves via a detergent dispensing means for dispensing a predetermined amount of a detergent agent into the cleaning liquid conduit upon commencement of a cleaning session. Hereby is achieved an enhanced cleaning result of the teat of the animal when the detergent agent is used together with the cleaning liquid.
Preferably, said apparatus further comprises means for controlling and synchronising the opening and closing of said cleaning liquid valves and said compressed-air valves. Hereby is achieved that the cleaning of the animal is allowed to be performed automatically.
Advantageously, each group of nozzle members comprises at least two elongated nozzle elements provided with a plurality of orifices for injecting cleaning liquid into the teat cleaning cup. Hereby is achieved an enhanced injection distribution of the cleaning liquid into the teat cleaning cup.
Preferably, said elongated nozzle element is arranged substantially vertically in said teat cleaning cup extending from a lowermost part of said teat cleaning cup to an uppermost part of said teat cleaning cup and where said orifices are distributed along the elongated nozzle element. Hereby is achieved that the whole length of the teat is cleaned when injecting cleaning liquid through the orifices.
Preferably, said orifices are angled so as to inject the cleaning liquid tangentially onto an inserted teat. Hereby is avoided a direct impact of the cleaning liquid onto a teat and an enhanced whirling motion of the cleaning liquid inside the teat cleaning cup is achieved.
In case there are two groups of nozzle members separated circumferentially in the teat cleaning cup, one of said groups of nozzle members is advantageously arranged on a first semi-circumferential side of the teat cleaning cup while the other group of nozzle members is arranged on the opposite semi-circumferential side of the teat cleaning cup. Hereby is achieved that the teat is deflecting from side to side when alternating the injection between the first and the second groups of nozzle members. Consequently, hidden parts of the teat is exposed for the injected cleaning liquid.
Advantageously, said first and second groups of nozzle members are symmetrically arranged on said first and second semi-circumferential sides of the teat cleaning cup. Hereby is achieved an uniformly distributed cleaning intensity of the teat.
Preferably, said method comprises the step of applying an under-pressure within the teat cleaning cup. Hereby is achieved an enhanced drainage of the cleaning liquid.
Advantageously, said method further comprises the step of adding a detergent agent to the cleaning liquid upon commencement of either one of said alternating injecting steps. Hereby is achieved an enhanced cleaning action of the teat.
Preferably, said method further comprises the step of using compressed-air and/or vacuum for injecting said cleaning liquid into the teat cleaning cup. Hereby, the injection of the cleaning liquid is facilitated.
Advantageously, said method further comprises the step of opening and closing relevant valves for controlling and synchronising said alternating injecting steps. Hereby is achieved controlled ways of injecting the cleaning liquid.
Preferably, said method further comprises the step of drying the teat from cleaning liquid by venting ambient air into the teat cleaning cup. Hereby is achieved that remaining cleaning liquid is removed from the teat cleaning cup.
Preferably, said method further comprises the step of stimulating the teat by repeatedly supplying compressed-air into the teat cleaning cup. Hereby is achieved that milk letdown is easier induced since the pressure in the teat cleaning cup fluctuates.
Advantageously, said method further comprises the step of increasing applied under-pressure within the teat cleaning cup for extracting pre-milk, subsequent to said teat cleaning session. Hereby is achieved that cleaning and pre-milking can be performed using the same cleaning device.
Preferably, the method and the apparatus for cleaning a teat is used in an automatic robot milking system. Hereby is achieved an automatically performed treatment with little human intervention. The performance of the treatment may also be adapted to the demands of a specific animal since a robot milking system is controlled by pre-recorded algorithms interpreting information from various sensors and detectors.